A yaw control system, which is an important component of wind turbine generator system (hereinafter referred to as generator system), is used to control the position of a generator system relative to wind to face the wind on the front side, to increase absorption efficiency of wind energy and to effectively reduce asymmetrical loads due to impellers not directly facing the wind. The goal of a yaw control system is to keep generator system operating in a wind direction range with high absorption efficiency of wind energy as much as possible.
However, the yaw control, is susceptible to the effect of wind shear, resulting in a lower reference accuracy provided for the yaw of the wind turbine generator system, which reduces the accuracy of yaw of the generator system, and hinders the improvement in the utilization rate of the wind energy.